JPH0623273B2 - Thermoplastic polymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic composition having improved flexibility and compression set, and excellent flex resistance and mechanical strength.

[Conventional technology]

A large number of thermoplastic compositions composed of polyamide and / or polyamide elastomer and rubber have been proposed. Patent relating to the composition of polyamide and olefin copolymer (JP-B-55-44108)
7-147519), or a homopolymer of polyamide and at least 80% gel content of 1,3-butadiene, 1,3-butadiene being styrene, vinylpyridine,
Patents relating to a composition comprising a copolymer copolymerized with acrylonitrile or methacrylonitrile (Japanese Patent Laid-Open No. 52-105952) are known.

However, since such a thermoplastic polymer composition is a material having a rubber-like elasticity and a thermoplastic property,
Compared with conventional vulcanized rubber, it is characterized in that it can be injection molded, extruded or blow molded in terms of processability. However, from the viewpoint of material properties, it has a drawback that the shape after deformation cannot be completely restored, that is, it is inferior in terms of compression set.

The former of the above patents proposes an improvement in mechanical strength due to the interaction of functional groups of polyamide and polyolefin, but this thermoplastic composition is inferior in compression set. Also, in the latter patent, it is proposed to improve tensile strength by melt-mixing a copolymer of polyamide and 1,3-butadiene and adding a vulcanizing agent for rubber to vulcanize the rubber. However, in this method, a copolymer of polyamide and 1,3-butadiene is cross-linked with a vulcanizing agent, so that vulcanization takes time, industrial productivity is poor, and reproducibility of the product is difficult to obtain, and vulcanization is difficult. It was revealed by the study by the present inventors that the rubber particles have large particle diameters and are not uniform, and are inferior in bending resistance and fluidity.

c. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention is to improve the flexible compression set, mechanical strength, and flex resistance of a composite composition of polyamide and / or polyamide elastomer and rubber.

d. MEANS FOR SOLVING THE PROBLEMS The present invention comprises (A) 20 to 99% by weight of a polyamide and / or polyamide elastomer and (B) 0.01 to a crosslinkable monomer.
A rubber component 80-1 having an average particle diameter of 10 mμ or less, which comprises 20% by weight and 0.01 to 20% by weight of a monomer having a carboxyl group and / or an epoxy group as a copolymerization component.
By blending with 1% by weight, a thermoplastic polymer composition having improved compression set, mechanical strength and flex resistance is provided.

The present invention is to crosslink a rubber component with a crosslinkable monomer and at the same time copolymerize a monomer having a carboxyl group and / or an epoxy group, to thereby obtain a polyamide and / or
Alternatively, it is intended to improve the compression molding strain and the mechanical strength and flex resistance by improving the resilience against deformation of the composition after being compounded with the polyamide elastomer.

Examples of the (A) polyamide of the present invention include polylactams such as nylon 6, nylon 11 and nylon 12; dicarboxylic acids and diamines such as nylon 4,6, nylon 6-6, nylon 6-10 and nylon 6-12. Polyamides obtained from; nylon 6 / 6-6, nylon 6 /
6-10, nylon 6/12, nylon 6 / 6-12,
Nylon 6/66 / 6-10, Nylon 6/66/12
And the like; semi-aromatic polyamides obtained from aromatic dicarboxylic acids such as nylon 6 / 6T (T; terephthalic acid component) and isophthalic acid, and metaxylene diamine or alicyclic diamine. Of these, nylon 11 and nylon 12 are most preferable.

As the polyamide elastomer, one synthesized by a condensation reaction of a polyether having a hydroxyl group at the chain end and a polyamide is used.

Examples of the polyether having a hydroxyl group at the chain end include a chain or branched polyoxyalkylene glycol such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol or a mixture thereof, or a copolyol derived from the above compound. It is ether. The average molecular weight of the polyether is generally 200 to 6,000, preferably 400 to 3,0.
00.

The ratio of the weight of polyoxyalkylene glycol to the weight of all components is usually 5 to 85%, preferably 10 to 5%.
It is 0%.

Further, as a polyamide, the number of carbon atoms in the hydrocarbon chain is 4
~ 14 lactams or amino acids, such as caprolactam, enantolactam, dodecalactam, undecanolactam, dodecanolactam, 11-amino-undecanoic acid or 12-aminododecanoic acid as starting material or dicarboxylic acid and diamine Condensation products such as, for example, hexamethylenediamine and adipic acid, azelaic acid, sebacic acid, and 1,12-dodecanedioic acid, and nylon 6-6 which is a condensation product of nonamethylene diami and adipic acid. , 6-9, 6-1
0, 6-12 and 9-6.

The diacid used as a chain limiter in the polyamide synthesis reaction likewise makes it possible to obtain a polyamide having a carboxylic acid at the end, but a dicarboxylic acid, preferably an aliphatic dicarboxylic acid having 4 to 20 carbon atoms, for example, They are succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid.

Alicyclic or aromatic diacids can also be used. These diacids are used in an amount that is in excess of that required to obtain a polyamide having the desired average molecular weight according to known calculation methods currently used in the field of polycondensation reactions.
The average molecular weight of the dicarboxylic acid polyamide is usually 300 to 1.
It is 5,000, preferably 800 to 5,000.

The polycondensation reaction for producing polyamide elastomer is carried out in the presence of a catalyst with stirring at 0.05-5 mmHg.
It is carried out at a temperature higher than the melting point of the components used under a moderately high vacuum. The temperature is selected so that the reaction components are maintained in a fluidized state. That is, it is generally 100 to 400 ° C, preferably 200 to 300 ° C.

The reaction time may vary generally from about 10 minutes to 10 hours, preferably about 1 to 7 hours.

The reaction time depends on the properties of the polyoxyalkylene glycol. It must then be long enough so that the final viscosity required to obtain a product with satisfactory properties as required for moldable and / or extrudable plastic materials can be obtained. I won't.

However, in order to obtain the desired product, the carboxylic acid groups and the hydroxyl groups must be in an equimolar relationship so that the polycondensation reaction occurs under optimum conditions.

The main component of the rubber component (B) used in the thermoplastic polymer composition of the present invention is acrylonitrile butadiene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber n-butyl acrylate-butadiene copolymer, n-butyl. Diene rubber such as (meth) acrylic acid alkyl ester-butadiene copolymer such as acrylate-acrylonitrile-butadiene copolymer, 2-ethylhexyl acrylate-acrylonitrile-butadiene copolymer, acrylic rubber, fluororubber, chloroprene rubber And rubber such as ethylene-propylene rubber. Among these acrylonitrile-
Butadiene rubber is most preferred. In the production of the rubber component, the above-mentioned (B) contains 0.01 to 20% by weight of a crosslinkable monomer (content in the rubber component after copolymerization), a carboxyl group and /
Alternatively, it can be produced by copolymerizing 0.01 to 20% by weight of a monomer having an epoxy group (content in the rubber component after copolymerization) in the coexistence of a monomer which is a main component of the rubber component. Thus, a rubber component having a gel content of 20% or more can be obtained.

In the rubber component used in the present invention, the particle size, gel content and amount of functional groups are extremely important.

The particle size of the rubber dispersed in the thermoplastic composition of the present invention is preferably 10 mμ or less, more preferably 1 mμ or less, particularly preferably 0.5 mμ or less, and most preferably 0.3 mμ or less. If the particle size of the rubber is large, the mechanical strength and the flex resistance are deteriorated, which is not preferable.

The gel content of the rubber component (B) used in the present invention must be 20% or more. Preferably 5
It is 0% or more, more preferably 70% or more. When the amount of the crosslinked rubber is less than 20%, the thermoplastic polymer composition of the present invention has a large compression set and the molded article does not restore, which is not preferable. The gel content can be controlled by the addition amount of the crosslinkable monomer. Examples of the crosslinkable monomer include aromatic compounds such as divinylbenzene, 1,3,5-trivinylbenzene, ester compounds such as diallyl phthalate and diallyl fumarate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate and tetra. Examples thereof include acrylic acid esters such as ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, diethylene glycol dimethacrylate, and triethylene glycol dimethacrylate.

The amount of the crosslinkable monomer used is 0.01 to 20% by weight, and if it is less than this amount, the desired gel content cannot be obtained. On the other hand, if the amount is larger than this amount, the flexibility is deteriorated and the cost is increased.

Examples of the monomer containing a carboxyl group include monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid, or dicarboxylic acids. Furthermore, an acid anhydride group of dicarboxylic acid or a monoalkyl ester represented by the following general formula,
Monoamides can also be used.

As a specific carboxyl group-containing vinyl monomer, In addition, succinic acid mono- (meth) acrylooxy ester, maleic acid mono- (meth) acrylooxy ester, phthalic acid mono- (meth) acrylooxy ester, hexahydrophthalic acid (meth) acryloyl Oxyester, succinic acid mono- (meth) acrylooxypropyl ester, maleic acid mono- (meth) acrylooxypropyl ester, phthalic acid mono (meth) acrylooxypropyl ester, hexahydrophthalic acid mono-
Examples thereof include (meth) acrylooxypropyl ester, adipic acid mono- (meth) acrylooxyethyl ester and malonic acid mono (meth) acrylooxyethyl ester. Among these vinyl monomers containing a carboxyl group, acrylic acid or methacrylic acid is preferably used.

As the vinyl monomer containing an epoxy group, all compounds containing a vinyl group and an epoxy group in the molecule can be used. Preferred epoxy group-containing vinyl compounds have the general formula [Wherein R is the same as the above formula].

Specific preferred compounds include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylic acid, glycidyl itaconate, and allyl glycidyl ether, and particularly preferred epoxy group-containing vinyl compounds are glycidyl acrylate and glycidyl methacrylate.
Allyl glycidyl ether. These epoxy group-containing vinyl compounds are used alone or in combination of two or more.

The content of the monomer having a carboxyl group and / or an epoxy group in the rubber component after copolymerization is 0.01 to 20% by weight, preferably 0.1 to 15% by weight, more preferably 0.5 to 10% by weight. Is. When the content is 0.01% by weight or less, no substantial effect is observed, and when the content is 20% by weight or more, the glass transition temperature of the rubber component is high and the cold resistance of the thermoplastic composition is poor.

The mixing ratio of the above components is 20 to 99% by weight of the polyamide (A) and / or polyamide elastomer, and 80 to 1% by weight of the rubber component (B). 20 polyamide components
If it is less than 0.1%, the processability is remarkably reduced and the thermoplastic property is impaired, and a practically preferable molded product cannot be obtained. The preferred mixing ratio is 40 to 90% by weight of the component (A),
Component (B) is 60 to 10% by weight.

In order to bring out the effects of the invention in the thermoplastic polymer composition of the present invention, it is preferable to set the mixing temperature to the melting point of the polyamide and / or the polyamide elastomer component (A) or higher. When the temperature of the polyamide and / or polyamide elastomer component during mixing is lower than the melting point, not only the torque during mixing becomes high, but also the mixing becomes insufficient and the physical properties of the resulting composition are sufficiently exhibited, which is not preferable. On the other hand, if the temperature during mixing is too high, the soft component of the rubber component (B) causes thermal decomposition deterioration and the like, and a composition having high physical properties cannot be obtained, which is not preferable.

Therefore, the mixing temperature is preferably 5 ° C or higher than the melting point of the polyamide and / or polylyamide elastomer,
More preferably, the temperature is raised by 10 ° C. or more, preferably 300
C. or lower, more preferably 280.degree. C. or lower.

In the production of the thermoplastic elastomer composition of the present invention,
As a device for melting and mixing the components, known devices such as an open mixing roll, a non-open Banbury mixer, an extruder, a kneader, and a continuous mixer can be used.

The thermoplastic elastomer composition of the present invention contains fillers such as calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, and asbestos within a range that does not impair fluidity and mechanical strength. , Alumina, barium sulphate, aluminum sulphate, calcium sulphate, basic magnesium carbonate, molybdenum disulfide, graphite, carbon fiber, glass fiber, etc. or colorants such as carbon black, ultramarine blue, titanium oxide, zinc white, red iron oxide, dark blue, azo Pigments, nitrone pigments, lake pigments, phthalocyanine pigments and the like can be added.

Also, process oil, or softening agent for mineral oil-based rubber called diextyl oil, dioctyl phthalate,
Phthalates such as dibutyl phthalate, diethyl phthalate, dimethyl phthalate, dipeptyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, diisononyl phthalate, dimethyl isophthalate, diundecyl phthalate, tricresyl phosphate, Triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimethyl phosphate, tributoxyethyl phosphate, tris-chloroethyl phosphate, tris-dichloropropyl phosphate, condensed phosphate ester, triphenyl phosphate,
Trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, trilauryl phosphate, tricetyl phosphate, tristearyl phosphate, trioleyl phosphate, and other phosphate esters, trimellitic octyl ester, Trimellitic acid isononyl ester, trimellitic acid isodecyl ester, and other trimellitic acid esters, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl adipate, diisobutyl adipate, dibutyl adipate, diisodecyl adipate, dibutyl diester Glycol adipate, di-2-ethylhexyl azelate, dioctyl azelate, diocty Sebacate, di-2-ethylhexyl sebacate, fatty acid esters such as methylacetylricinoleate, pyromellitic acid esters such as octyl pyromellitic acid ester, epoxidized soybean oil, epoxidized linseed oil, epoxidized fatty acid alkyl ester (for example, , Epoxidized fatty acid octyl ester) and the like, and plasticizers such as adipic acid ether ester, polyether ester, polyether and other polyether plasticizers may be used alone or in combination of two or more. it can.

The plasticizer is used for the purpose of improving the fluidity and lowering the hardness of the composition of the present invention. Depending on the purpose of use of the plasticizer, the plasticizer is selectively used as the component (A) or the component (B) of the present invention. Those that enter, or those that enter both components, can be appropriately selected.

When the above-mentioned plasticizer is used in the composition of the present invention, phthalic acid esters, phosphoric acid esters, epoxy plasticizers, polyether plasticizers and the like are preferable from the viewpoint of bleeding property, and more preferable are phthalic acid esters and polyesters. It is an ether plasticizer.

Phthalates are mainly effective in plasticizing component (A), and polyether plasticizers are mainly effective in plasticizing component (B).

When using phthalates, it is preferable to use one having a molecular weight of 300 or more, preferably 400 or more, in an amount of 20% or more based on the total amount of the plasticizer for the purpose of reducing the amount of volatile components at the time of injection molding.

Among the polyether-based plasticizers, preferred are polyether ester-based ones having a molecular weight of 400 or more.

The plasticizer is used in the range of 1 to 200 parts by weight based on 100 parts by weight of the component (A) + (B) of the present invention. In addition, liquid NBR, liquid acrylic rubber, liquid polybutadiene rubber and other liquid rubber, benzene sulfonate butylamide, Yoshitomi Pharmaceutical Co., Ltd. POBO, Shin Nippon Rika Co., Ltd. Sanso Sizer N400 By blending in a range that does not impair the fluidity, the fluidity can be improved.

Furthermore, during mixing, a phenylenediamine antioxidant (Nocrac CD, Nocrac T manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)
D, Nocrac G1, Nocrac WHITE), imidazole type antioxidants (Ouchi Shinko Chemical Co., Ltd. Nocrack MB, Nocrack MMB), hindered phenolic antioxidants (BHT, Nocrac 300), various UV absorbers Can be added.

Further, aromatic vinyl-conjugated diene block copolymers such as styrene-butadiene block polymer, styrene-butadiene-styrene block polymer, styrene-butadiene-styrene radial tereblock polymer and hydrides of the block copolymer. , Polypropylene, polyvinyl chloride, polycarbonate, PET, PBT, polyacetal, epoxy resin, vinylidene fluoride, polysulfone, ethylene-vinyl acetate copolymer, PPS resin, polyether ether ketone, PPO resin, styrene-methyl methacrylate copolymer Polymers, styrene-maleic anhydride copolymers, rubber-modified PPO resins, styrene-maleimide-based copolymers, rubber-modified styrene-maleimide-based copolymers, elastomers other than polyamide-based elastomers such as polyester-based It can be blended such as appropriate resin or a thermoplastic elastomer, such elastomer. The use of the thermoplastic elastomer composition of the present invention includes body panels, bumper parts, molding side shields, steering wheels, joint boots, strut suspension boots, steering wheel and other automotive parts, shoe soles,
Footwear such as sandals, electric wire coating, connectors, electric parts such as cap plugs, golf club grips, baseball bat grips, grips for automobiles and motorcycles, swimming fins, leisure products such as underwater glasses, gicket,
Waterproof cloth, hydraulic hose, fuel hose, freon hose, power steering hose, coil tube, packing, roll,
Garden hose, belt, damping material for damping steel plate keyboard, curl cord, coupling, dust boot, O-
It can be considered to be used as a material for rings.

e. EXAMPLES Next, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples as long as the gist thereof is not exceeded.

The physical properties were measured by the following methods.

Example 1 Using the emulsion polymerization formulation shown below, it was produced by carrying out emulsion polymerization under the following polymerization conditions in an autoclave with an internal volume of 20.

Emulsion polymerization formulation After the polymerization conversion reached 90%, 0.2 part of hydroxylamine sulfate was added to 100 parts of the monomer to terminate the polymerization. The obtained polymerization product was heated and the residual monomer was recovered by steam distillation under reduced pressure at about 70 ° C., and then 2 parts of alkylated phenol was added as an antiaging agent, and then the latex obtained was put into a pressure resistant tube. Put in, 11
The latex was coagulated by heating to 0 ° C., and then the coagulated product was vacuum dried at 80 ° C. to obtain a crosslinked carboxy-modified NBR rubber.

1 g of the crosslinked carboxy-modified NBR rubber obtained above was shredded, 100 g of methyl ethyl ketone was added, and the mixture was allowed to stand at 25 ° C. overnight. Then, the gel was precipitated using a high speed centrifuge, and the supernatant was removed by filtration. Methyl ethyl ketone was added to the obtained gel, and the mixture was stirred, then centrifuged, and the supernatant was filtered off. Further, the same operation was repeated twice. As a result, 0.83 g of gel rubber was obtained. Therefore, the gel content in the crosslinked carboxy-modified NBR rubber was calculated to be 83%. 1.5 kg of Nylon-11 (Toray Rilsan BMN O P20) and 1.5 kg of the crosslinked carboxyl-modified NBR rubber obtained above were mixed at 200 ° C. using a 40 mmφ extruder, dried, and then dried by a 10 ounce injection molding machine. A sheet having a thickness of 2 mm, a length of 12 cm and a width of 10 cm was formed. The obtained thickness is 2 mm, length is 12 cm,
A JIS No. 3 dumbbell-shaped test piece was punched out from a sheet having a width of 10 cm according to the method of JIS K-6301.
A tensile test was performed on this test piece according to the method of JIS K-6301. The hardness and compression set were also measured according to the method of JIS K-6301. The results are shown in Table-1.

Examples 2 to 4 Nylon-11 of Example 1 and crosslinked carboxy modified NBR
The amount of rubber is 2.1kg, 0.9kg and 2.7kg, 0.3kg and 0.9k respectively
g and 2.1 kg were mixed and mixed and evaluated in the same manner as in Example 1. The results are shown in Table-1.

Examples 5 to 8 A composition with a crosslinked carboxy-modified NBR was similarly evaluated using a polyamide elastomer (PEBAX5533 manufactured by Atchem Co.) instead of Nylon-11 of Example 1.
The results are shown in Table-1.

Example 9 By changing the amount of the crosslinkable monomer (divinylbenzene) of the crosslinked carboxy-modified NBR of Example 6 to 3% and varying the gel amount of the crosslinked carboxy-modified NBR (content of crosslinked rubber), Evaluation was made in the same manner as in Example 6. The results are shown in Table-1.

Example 10 A composition was produced using the crosslinked epoxy-modified NBR of Example 6 and evaluated. The results are shown in Table-1.

However, the crosslinked epoxy-modified NBR was obtained by changing the composition of the monomer of Example 1 as follows.

Comparative Example 1 Instead of the crosslinked carboxy-modified NBR of Example 6, crosslinked NBR without carboxy modification (JSRN manufactured by Japan Synthetic Rubber)
BRN2105) was used. The results are shown in Table-2.

In the case of cross-linked NBR that has not been modified, the tensile strength of the composition,
It can be seen that the elongation is extremely low and the mechanical properties are practically inferior.

Comparative Example 2 The dynamic vulcanization method proposed by the method of JP-A-52-105925 was carried out using a peroxide. Since the dynamic vulcanization method requires time, dynamic vulcanization was performed using a bravader.

Polyamide elastomer (PEBAX55 manufactured by Atochem Co., Ltd.
33) 25 g and NBR (JSRNBR made by Japan Synthetic Rubber Co., Ltd.
N230) 180 g of rubber 25 g using Brabender
After melt-kneading at 60 ° C. for 5 minutes at a rotation speed of 60 rpm, 0.5 g of Perhexa25B as a peroxide was added and dynamic crosslinking was further performed for 5 minutes. Immediately after the kneading, a sheet having a thickness of 1 mm was formed by a delivery roll. The composition was examined for fluidity using a Koka type flow tester, but no substantial flow was observed even at 230 ° C., and it was judged that injection molding was impossible, and molding was carried out by a press.

Heat for 10 minutes with a hot press at 190 ℃, then 30
The mixture was transferred to a cold press at 0 ° C., and pressed while applying a pressure of 100 kg / cm ² G while cooling. A JIS No. 3 dumbbell-shaped test piece was punched from the obtained sheet having a thickness of 1 mm, a length of 11 cm, and a width of 9 cm according to the method of JIS K-6301, and a tensile test was performed on this test piece according to the method of JIS K-6301. Carried out. The hardness and compression set were also measured according to the method of JIS K-6301. The results are shown in Table-2.

The composition produced by the dynamic vulcanization method is not only inferior in fluidity, but also has low mechanical strength and is not expected to be practically usable.

Comparative Example 3 Polymerization was carried out without adding an emulsifier at the time of moving the crosslinked carboxyl-modified NBR shown in Example 1. The rubber after polymerization was manufactured into a powder rubber having an average particle diameter of 50 mμ by a pulverizer, and melt-mixed with a polyamide elastomer in the same manner as in Example 6, and evaluated. The results are shown in Table-2. Low mechanical strength,
The surface of the composition was also disordered. It can be seen that the particle size of rubber is also required to be small.

Comparative Example 4 A carboxyl-modified NBR was produced according to the formulation of Example 1 without adding a crosslinkable monomer. Next, a composition was produced and physical properties were evaluated in the same manner as in Example 6. Table of results
2 shows. It can be seen that when the NBR is not crosslinked, the compression set is large, which is not desirable as a thermoplastic elastomer.

Comparative Example 5 3 parts of zinc white was added to the composition of Comparative Example 4 and the mixture was melt-kneaded and then evaluated. The results are shown in Table-2. Vulcanization with metal salts did not improve compression set.

Example 11 The crosslinked epoxy NBR of Example 10 and Nylon 12 Daicel L2121 manufactured by Daicel were blended in the proportions shown in Table-1. The results are shown in Table-1.

Example 12 The composition of the monomer of Example 1 was changed as follows, and a crosslinked carboxy-modified styrene-butadiene copolymer rubber was obtained, and then blended and evaluated in the same manner as in Example 6. The results are shown in Table-1.

Comparative Example 6 A crosslinked carboxyl-modified NBR having a bull content of 13% was obtained by changing the amount of divinylbenzene in the production of the crosslinked carboxy-modified NBR of Example 1 to 0.001 part. Blended as in Example 6. The results are shown in Table-2.

Evaluation of Flexing Resistance The thermoplastic compositions obtained in Examples 6 and 10 and Comparative Example 2 were evaluated by a loss bending tester according to JIS K6301. The crack growth length due to bending is shown in FIG.

It can be seen that the thermoplastic composition obtained according to the present invention has excellent flex resistance.

Examples 13 to 16 Polymerization was carried out under the same conditions as in Example-1, except that the following monomer composition was used instead of the following monomer composition to obtain a rubber having a gel content of 88%.

 Monomer composition (part) acrylonitrile 26 butadiene 14 n-butyl acrylate 52.5 methacrylic acid 6 divinylbenzene 1.5 polyamide elastomer (PEBAX) 5533) and above
The rubber component and the plasticizer were added in the proportions shown in Table 3 as in Example 1.
It mixed and evaluated. The evaluation results are shown in Table-3.

Comparative Example 7 Except for divinylbenzene of Example 10, a non-crosslinked epoxy-modified NBR was obtained by the following formulation.

Monomer Acrylonitrile 34 parts Butadiene 60 parts Glycidyl methacrylate 6 parts Total 100 parts The obtained epoxy-modified NBR was kneaded and molded with a polyamide elastomer in the same manner as in Example 10, and the physical properties were evaluated. The results are shown in Comparative Example 7. Compared with Comparative Example 10, tensile strength and compression set are significantly inferior.

g. EFFECTS OF THE INVENTION The polyamide and / or polyamide elastomer of the present invention is melt-mixed with a rubber pre-crosslinked having a gel content of 20% or more and carboxy-modified or epoxy-modified to obtain compression set, flex resistance, mechanical strength, A thermoplastic elastomer having excellent heat resistance and oil resistance and excellent properties as an industrial material can be obtained.

[Brief description of drawings]

FIG. 1 shows the relationship between the number of bends and the crack growth of the compositions of Examples 6 and 10 and Comparative Example 2.

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Claims (1)

[Claims] 1. A) 20 to 99% by weight of a polyamide and / or polyamide elastomer component and 0.01 to 20% by weight of a crosslinkable monomer and 0.01 to 20% by weight of a monomer having a carboxyl group and / or an epoxy group. 80 to 1% by weight of a rubber component containing and as a copolymerization component, having an average particle diameter of 10 mμ or less and a gel content of 20% or more.
A thermoplastic polymer composition comprising: